Application Of Pyrroloquinoline Quinone In Preparation Of Medicament Used For Preventing And Treating Acute Altitude Sickness And Acute Altitude Hypoxia Injury

ABSTRACT

The present invention relates to an application of pyrroloquinoline quinone (PQQ) in the preparation of a medicament used for preventing and treating acute altitude sickness and acute altitude hypoxia injury. Pyrroloquinoline quinone has the effect of preventing and treating acute high altitude hypoxia injury, and as a drug for the prevention and treatment of acute altitude sickness, the efficacy thereof is equivalent to that of acetazolamide, however acetazolamide has many toxic side effects; meanwhile, as a coenzyme, pyrroloquinoline quinone has the advantages of low toxicity and is easily acceptance by patients. In addition, by means of exhaustive swimming experiments of mice under the conditions of hypoxic exposure, PQQ has been shown to have the feature characteristics of improving the working capabilities of a subject at a high altitude, however acetazolamide has not been found to have said effect.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage application of the PatentCooperation Treaty (PCT) international application titled “ApplicationOf Pyrroloquinoline Quinone In Preparation Of Medicament Used ForPreventing And Treating Acute Altitude Sickness And Acute AltitudeHypoxia Injury”, international application number PCT/CN2019/104174,filed in the China National Intellectual Property Administration (CNIPA)on Sep. 3, 2019, which claims priority to and the benefit of the patentapplication titled “Application Of Pyrroloquinoline Quinone InPreparation Of Medicament Used For Preventing And Treating AcuteAltitude Sickness And Acute Altitude Hypoxia Injury”, patent applicationnumber 201811022046.8, filed in the China National Intellectual PropertyAdministration (CNIPA) on Sep. 3, 2018. The specifications of the abovereferenced patent applications are incorporated herein by reference intheir entirety.

FIELD OF THE INVENTION

The present invention relates to a new application of pyrroloquinolinequinine, specifically, relates to an application of pyrroloquinolinequinone (PQQ) in preparation of medicament for preventing and treatingacute altitude hypoxia injury.

BACKGROUND

Low pressure and low oxygen in plateau areas are main environmentalfactors in plateau areas and main pathogenic factors of altitudesickness. With the development of the western part of the country andthe opening of the Qinghai-Tibet Railway, more and more people work andtravel on the plateau is increasing. People pay more and more attentionto health maintenance of people entering the plateau area. It has becomean important direction of plateau medicine or health care productresearch.

Currently, treatment for high altitude polycythemia requires more than250 mg of acetazolamide daily. However, acetazolamide can easily causeadverse reactions such as perchloric metabolic acidosis, limb numbness,gastrointestinal discomfort, confusion of consciousness, nausea,anorexia, drowsiness, polyuria and tinnitus. The tissue/organdistribution, subcellular localization and physiological function ofthem are quite different, because carbonic anhydrase has 12 isoenzymeswith enzymatic catalytic activity. Acetazolamide has strong inhibitoryeffects on a variety of carbonic anhydrase isozymes. Research on enzymeinhibitors will mainly focus on finding carbonic anhydrase inhibitorswith strong selectivity and high tissue specificity.

Pyrroloquinoline quinone (PQQ) is a coenzyme different from pyridinenucleotides (NAD, NADP) and riboflavin (FMN, FAD). It is anoxidoreductase prosthetic group that acts as an electron donor andreceptor participates in the electron transfer of the respiratory chainin the redox process, has strong free radical scavenging ability, andhas many physiological functions. It plays an important role in theprocess of stimulating metabolism of organisms, promoting growth anddevelopment, protecting liver injury, degrading ethanol, anti-oxidationand anti-radiation. However, there is no research and application reporton uses of pyrroloquinoline quinone for preventing and treating acutealtitude hypoxia injury.

SUMMARY OF THE INVENTION

In order to overcome the above shortcomings, the present inventionprovides an application of pyrroloquinoline quinone (PQQ) in thepreparation of a medicament for preventing and treating acute altitudesickness and acute altitude hypoxia injury.

Pyrroloquinoline quinone of the present invention has effects ofpreventing and treating acute altitude hypoxia injury. Its efficacy ofpyrroloquinoline quinone is equivalent to that of acetazolamide in amedicine for preventing and treating acute altitude sickness. Butacetazolamide has serious side effects. Pyrroloquinoline quinone as acoenzyme has advantages of low toxicity and easy acceptance by patients.In addition, PQQ shows through exhaustive swimming experiments in miceunder low oxygen exposure conditions that pyrroloquinoline quinone hasfunction characteristics of improving the working ability of the plateaubodies, but no effect of Acetazolamide is found.

DETAILED DESCRIPTION OF THE INVENTION

The following examples are used to further specifically illustrate thepresent invention, but not limited to the following examples and therange of process parameters in the examples.

1. Material

1.1 Experimental Animals

Kunming mice, clean grade, female/male, weight 16-22 g, provided by theAnimal Center of the Academy of Military Medical Sciences.

Wistar rat, clean grade, male, weight 160-220 g, provided by the AnimalCenter of the Academy of Military Medical Sciences.

1.2 Main Reagents

PQQ (XINCHANG PHARMACEUTICAL FACTORY, batch number: 150502)

Acetazolamide, content: 99.9%, (Chengdu Youlian Biotechnology Co., Ltd.,batch number: 260905091)

NO kit, Coomassie brilliant blue kit (Beijing Puerweiye BiotechnologyCo., Ltd.)

ET-1 Enzyme-linked Immunoassay (ELISA) Kit (Beijing Puer WeiyeBiotechnology Co., Ltd.)

Oxidative stress SOD, CO, MDA detection kit (Nanjing JianchengTechnology Co., Ltd.)

Test kit for adenosine triphosphate, lactic acid, hepatic glycogendetection kit (Nanjing Jiancheng Technology Co., Ltd.)

Pentobarbital sodium (American Sigma company).

1.3 Main Instruments

Multi-factor compound environment simulation medical scienceexperimental chamber (AVIC Guizhou Fenglei Aviation Ordnance Co., Ltd.)

FlexStation 3 multi-functional enzyme label instrument workstation (USMolecular Devices Company)

7180 Automatic blood biochemical analyzer (Hitachi, Japan)

Heraeus low-temperature high-speed centrifuge (Germany Kendro Company)

Electronic balance (Germany Sartorius Company)

Ultra-low temperature refrigerator (Japan Sanyo Corporation)

2. PQQ Anti-Acute High Altitude Hypoxia Injury Experiment

2.1 Rat Acute Cecompression Hypoxia Experiment

Select healthy Wistar rats weight 160-200 g, half female and half male.After feeding for 3 days, these Wistar rats are randomly divided intoten groups according to their body weight, each group has 16±2 rats. Thegroups are divided as follows: five groups of the hypoxic exposure drugtest group, respectively, are given 0.91 mg/kg, 1.83 mg/kg, 3.66 mg/kg,7.31 mg/kg, and 14.63 mg/kg drugs. One group of hypoxia exposurepositive acetazolamide control group is given 0.11 g/kg acetazolamide;one group of hypoxia model group and one group of normal oxygen controlgroup, given a corresponding volume of solvent. In addition, set up onegroup of normal oxgen PQQ control group (given PQQ 3.66 mg/kg) and onegroup of normal oxygen acetazolamide control group (given 0.11 g/kgacetazolamide). After continuous intragastric administration for 7 days,the animals in the hypoxic exposure group are simultaneously put intothe decompression and hypoxia compound experimental chamber, the hatchis closed, and the pressure is reduced at a speed of 10 m/s. After beingraised to an altitude of 6000 m and maintained for 8 hours, the speed in10 m/s drops is reduced to normal altitude, open the hatch, and thentake out the animal, collect blood samples (after standing for 1 hour,the supernatant is centrifuged and stored at −20° C.), and liver tissuesamples. Detection indicator includes body weight, serum blood glucose,ATP, lactic acid, endothelin, nitric oxide, SOD, CO, MDA related tooxidative stress, and total protein, albumin, triglycerides, totalcholesterol, high-density lipoprotein cholesterol, low-densitylipoprotein cholesterol, glutamic pyruvic transaminase, total bilirubin,gluamic oxalacetic transaminase, serum urea nitrogen, creatinine, uricacid, lactate dehydrogenase, creatine kinase, α-hydroxybutyratedehydrogenase; liver ATP, hepatic glycogen. Except that the formaloxygen control animal group is not put into the decompression andhypoxia compound experimental chamber, other experimental conditions anddetection indicators are the same.

2.2 Exhaustive Swimming Experiment in Mice Exposed to High AltitudeHypoxia

Select healthy male Kunming mice weight 18-22 g. After feeding for 3days, they are randomly divided into seven groups according to theirbody weight, each group has 10±1 mice. The groups are divided asfollows: 5 groups of the drug test group, respectively, are given 1.32mg/kg, 2.64 mg/kg, 5.28 mg/kg, 10.56 mg/kg, and 21.12 mg/kg drugs bygavage administration. One positive drug control group of theacetazolamide is given 0.16 g/kg acetazolamide; one negative controlgroup is given a corresponding volume of solvent. After administrationfor 7 days, select an exhaustive swimming experiment under hypoxicconditions perform physical work ability evaluation; the observationindex is an exhaustive swimming time. In the decompression and hypoxiacompound laboratory chamber, decompression hypoxia is performed to analtitude of 6000 m, the swimming box is filled with water at a depth of40 cm and the water temperature is 25° C. The animal is placed in theswimming box, and use a stopwatch to record a time from the start ofswimming to exhaustion of the animal. Exhaustive swimming time is thetime when an animal still cannot surface for 9 s after sinking.

3. Detection Method

3.1 Determination of Nitric Oxide Content in Serum

Nitric oxide has very reactive chemically, and its metabolism in thebody quickly turns to NO²⁻ and NO³⁻, and NO²⁻ further turns to NO³⁻.This method uses nitrate reductase specificity reduce NO³⁻ to NO²⁻, andthen determine the level of its concentration by displaying shades ofcolor. Operate according to the kit instructions, measure the absorbanceof each tube at a wavelength of 550 nm, and then calculate the contentof nitric oxide of the sample to be tested according to the formula.

3.2 Determination of Serum Endothelin-1 Content

To the coated microwells pre-coated with rat endothelin (endothelin-1)capture antibody, add in sequence specimens, standards, and HRP-labeleddetection antibody, and then incubate and wash thoroughly. Use asubstrate TMB for color development. TMB is converted into blue underthe catalysis of peroxidase and converted into the final yellow colorunder the action of acid. The color intensity is positively correlatedwith the rat endothelin (endothelin-1) in the sample. Measure theabsorbance (OD value) by a microplate reader at a wavelength of 450 nm,take the concentration of the standard as the abscissa, and take thecorresponding OD value as the ordinate, draw a linear regression curveof the standard, and calculate the concentration of each sampleaccording to the curve equation.

3.3 Determination of Oxidative Stress Indicators such asMalondialdehyde, Superoxide Dismutase, Total Antioxidant Capacity

Determination of malondialdehyde: The malondialdehyde in the degradationproduct of lipid peroxide is condensed with thiobarbital (TB A) to forma red product with a maximum absorption peak at 532 nm. Operateaccording to the instructions, and then measure the absorbance value ofeach tube, and afterwards calculate the content of malondialdehyde inthe sample to be tested according to the formula.

Determination of superoxide dismutase: Superoxide anion free radicals(O²⁻) are generated through the reaction system of xanthine and xanthineoxidase. The latter oxidizes hydroxylamine to form nitrite. It appearspurplish red under the action of chromogenic agent. Measure itsabsorbance by a visible light spectrophotometer. When the measuredsample contains superoxide dismutase, it has specific inhibitory effecton superoxide anion free radicals, make formed nitrite reduced. Theabsorbance value of the measuring tube is lower than that of the controltube during colorimetry. The superoxide dismutase activity in the testedsample can be calculated by formula calculation. Operate according tothe instructions, measure the absorbance value of each tube at awavelength of 550 nm, and then calculate the activity of superoxidedismutase in the sample to be tested according to the formula.

Determination of total antioxidant capacity (T-AOC): Fe³⁺ can be reducedto Fe²⁺ by using antioxidant substances in the body. The latter can forma stable complex with phenanthrophins and measure its antioxidantcapacity by colorimetry. Operate according to the kit instructions,measure the absorbance of each tube at a wavelength of 520 nm, and thencalculate the total antioxidant capacity in the sample to be testedaccording to the formula.

3.4 Determination of Adenosine Triphosphate, Lactic Acid and LiverGlycogen

Determination of adenosine triphosphate (ATP): Perform enzyme-linkedimmunosorbent assay by double-antibody one-step sandwich method. To thecoated microwells pre-coated with rat adenosine triphosphate (ATP)capture antibody, add in sequence the specimens, standard, andHRP-labeled detection antibody, and then incubate and wash thoroughly.Use a substrate TMB for color development, TMB is converted into blueunder the catalysis of peroxidase and converted into the final yellowcolor under the action of acid. The color intensity is positivelycorrelated with the rat adenosine triphosphate (ATP) in the sample.Measure the absorbance (OD value) by a microplate reader at a wavelengthof 450 nm, take the concentration of the standard as the abscissa, andtake the corresponding OD value as the ordinate, draw a linearregression curve of the standard, and calculate the concentration ofeach sample according to the curve equation.

Determination of lactic acid (LC): Perform enzyme-linked immunosorbentassay by double-antibody one-step sandwich method. To the coatedmicrowells pre-coated with rat lactic acid (LC) capture antibody, add insequence the specimens, standard, and HRP-labeled detection antibody,and then incubate and wash thoroughly. Use a substrate TMB for colordevelopment. TMB is converted into blue under the catalysis ofperoxidase and converted into the final yellow color under the action ofacid. The color intensity is positively correlated with the rat lacticacid (LC) in the sample. Measure the absorbance (OD value) by amicroplate reader at a wavelength of 450 nm, take the concentration ofthe standard as the abscissa, and take the corresponding OD value as theordinate, draw a linear regression curve of the standard, and thencalculate the concentration of each sample according to the curveequation.

Determination of liver glycogen (GC): Perform enzyme-linkedimmunosorbent assay by double-antibody one-step sandwich method. To thecoated microwells pre-coated with rat liver glycogen (GC) captureantibody, add in sequence the specimens, standard, and HRP-labeleddetection antibody, and then incubate and wash thoroughly. Use asubstrate TMB for color development, TMB is converted into blue underthe catalysis of peroxidase and converted into the final yellow colorunder the action of acid. The color intensity is positively correlatedwith the rat liver glycogen (GC) in the sample. Measure the absorbance(OD value) by a microplate reader at a wavelength of 450 nm, take theconcentration of the standard as the abscissa, and take thecorresponding OD value as the ordinate, draw a linear regression curveof the standard, and calculate the concentration of each sampleaccording to the curve equation.

3.5 Determination of Blood Biochemical Indexes and Blood Homocysteine

Measure blood glucose, total protein, albumin, triglycerides, totalcholesterol, high-density lipoprotein cholesterol, low-densitylipoprotein cholesterol, glutamic-pyruvic transaminase, total bilirubin,glutamic oxalacetic transaminase, serum urea nitrogen, creatinine, uricacid, lactate dehydrogenase, creatine kinase, α-hydroxybutyratedehydrogenase, blood homocysteine by using an automatic bloodbiochemical analyzer.

4. Statistical Analysis

The measurement data is processed by t-test and variance analysis, andthe experimental results are expressed as mean±standard error (x±s);count data are expressed by using x² test and direct probability methodP<0.05 to indicate that the difference has significant.

5. Experimental Results of PQQ's Anti-Acute Altitude Hypoxia Injury inMice

5.1 Hypoxia Tolerance Test of simulated 10000 m Altitude AcuteDecompression in Mice

5.1.1 Single Dose Test

TABLE 1 Mice weight before hypoxia tolerance test of simulated 10000 maltitude acute decompression in mice (single dose test) Group Male(g)Female(g) Negative control (equal volume of water) 19.38 ± 0.53 16.90 ±1.33 Acetazolamide positive drug control 19.47 ± 0.57 17.31 ± 1.22group(0.16 g/kg) PQQ drug dose group I (2.64 mg/kg) 19.71 ± 0.52 17.25 ±1.23 PQQ drug dose group II (5.28 mg/kg) 19.51 ± 0.68 17.32 ± 1.35 PQQdrug dose group III(10.56 mg/kg) 19.16 ± 0.34 17.24 ± 0.96

It can be seen from Table 1 that there is no statistically significantdifference in the body weight of male and female mice of each groupbefore the experiment (P>0.05).

5.1.2 Administration for Three Days

TABLE 3 Mice weight before hypoxia tolerance test of simulated 10000 maltitude acute decompression in mice (administration for three days)Group Male(g) Female(g) Negative control (equal volume of water) 19.38 ±1.41 18.12 ± 1.23 Acetazolamide positive drug control 18.29 ± 0.85 17.80± 0.94 group(0.16 g/kg) PQQ drug dose group I (1.32 mg/kg) 19.97 ± 0.8418.22 ± 1.16 PQQ drug dose group II (2.64 mg/kg) 19.65 ± 0.83 18.79 ±1.14 PQQ drug dose group III (5.28 mg/kg) 20.16 ± 1.18 18.10 ± 0.76 PQQdrug dose group IV (10.56 mg/kg) 19.73 ± 0.85 17.95 ± 1.14 PQQ drug dosegroup V (21.12 mg/kg) 19.28 ± 0.95 18.48 ± 1.01

It can be seen from Table 3 that there is no statistically significantdifference in body weight of the male and female mice of each groupbefore the experiment (P>0.05).

5.1.3 Administration for Seven Days

TABLE 5 Changes of mice weight before hypoxia tolerance test ofsimulated 10000 m altitude acute decompression in mice (administrationfor seven days) Male(g) Female(g) Group 1 day 7 days 1 day 7 daysNegative control (equal volume 16.62 ± 2.64 22.11 ± 4.05 17.89 ± 1.4422.48 ± 1.94 of water) Acetazolamide positive drug 17.31 ± 1.58 21.43 ±2.79 17.58 ± 1.93 19.69 ± 3.52 control group(0.16 g/kg) PQQ drug dosegroup I (1.32 mg/kg) 18.46 ± 1.36 22.19 ± 2.69 18.10 ± 1.19 21.36 ± 1.98PQQ drug dose group II (2.64 mg/kg) 18.31 ± 1.01 23.51 ± 3.09 18.19 ±1.24 21.40 ± 1.92 PQQ drug dose group III (5.28 mg/kg) 18.38 ± 1.8522.04 ± 3.25 17.95 ± 1.28 22.71 ± 1.38 PQQ drug dose group IV (10.56mg/kg) 18.26 ± 1.15 22.41 ± 1.79 17.99 ± 1.41 22.66 ± 1.68 PQQ drug dosegroup V (21.12 mg/kg) 18.00 ± 1.78 23.54 ± 3.92 18.35 ± 1.62 23.94 ±2.10

It can be seen from Table 5 that there is no statistically significantdifference in body weight of the male and female mice of each groupbefore the experiment (P>0.05)., There is no statistically significantdifference in body weight of male and female mice of each group afteradministration for 7 days (P>0.05).

TABLE 7 Changes of male mice weight before hypoxia tolerance test ofsimulated 10000 m altitude acute decompression in mice (administrationfor seven days) (repeat the experiment in male mice after administrationfor seven days) Male(g) Group 1 day 7 days Negative control (equalvolume 19.36 ± 1.24 25.79 ± 4.00 of water) Acetazolamide positive drug19.53 ± 0.93  21.35 ± 2.47** control group (0.16 g/kg) PQQ drug dosegroup I (1.32 mg/kg) 19.84 ± 1.84 27.14 ± 2.66 PQQ drug dose group II(2.64 mg/kg) 19.66 ± 1.08 26.78 ± 3.14 PQQ drug dose group III (5.28mg/kg) 19.75 ± 1.27 26.47 ± 2.88 PQQ drug dose group IV (10.56 mg/kg)19.90 ± 1.06 27.33 ± 2.27 PQQ drug dose group V (21.12 mg/kg) 19.85 ±1.00 26.73 ± 2.37

It can be seen from Table 7 that there is no statistically significantdifference in the body weight of the male mice of each group before theexperiment (P>0.05). After administration for 7 days, compared with thecontrol group, the mice weight in the acetazolamide-positive drugcontrol group is decreased (P<0.05), and but there is no statisticallysignificant difference in body weight in each PQQ drug dose group(P>0.05).

5.1.4 14 Days of Administration

TABLE 9 Changes of mice weight before hypoxia tolerance test ofsimulated 10000 m altitude acute decompression in mice (administrationfor 14 days) Male(g) Female(g) Group 1 day 7 days 14 days 1 day 7 daysNegative control (equal volume 16.33 ± 1.66 22.61 ± 1.83 28.82 ± 2.7715.82 ± 1.72 21.87 ± 2.03 of water) Acetazolamide positive drug  14.66 ±1.52*  16.29 ± 3.25**  21.16 ± 3.61** 15.24 ± 0.89  19.35 ± 3.12*control group(0.16 g/kg) PQQ drug dose group I (1.32 mg/kg) 16.36 ± 1.4722.88 ± 1.78 30.85 ± 2.32 16.13 ± 1.20 20.45 ± 1.37 PQQ drug dose groupII (2.64 mg/kg) 16.63 ± 1.87 22.58 ± 1.41 28.13 ± 2.70 15.75 ± 1.0721.41 ± 1.62 PQQ drug dose group III (5.28 mg/kg) 17.01 ± 1.91 23.68 ±2.02 29.44 ± 2.15 15.63 ± 1.12 20.47 ± 2.11 PQQ drug dose group IV(10.56 mg/kg) 16.58 ± 1.68 23.13 ± 1.73 19.58 ± 2.11 15.84 ± 1.33 21.68± 1.66 PQQ drug dose group V (21.12 mg/kg) 16.86 ± 1.71 23.67 ± 1.7730.81 ± 2.76 15.68 ± 0.91 20.10 ± 2.07 *p < 0.05, **p < 0.01 VS negativecontrol group

It can be seen from Table 9 that compared with the negative controlgroup, there is no statistically significant difference in the miceweight of the male and female of each group before administration(P>0.05). After administration for 7 days, the male and femaleacetazolamide positive drug control groups had lower body weights thantheir corresponding negative control groups, and has a statisticallysignificant difference (P<0.05). Compared with its negative controlgroup, the body weight of each PQQ drug dose group has no statisticallysignificant difference (P>0.05). After administration for 14 days, thebody weight of the male and female acetazolamide-positive drug controlgroups is lower than that of the negative control group, and has astatistically significant difference (P<0.05). Compared with the femalenegative control group, the body weight of female mice PQQ drug-dosegroups III and V is decreased, and has a statistically significantdifference (P<0.05). Compared with their corresponding negative controlgroup, The body weight of female and male mice in other PQQ drug dosegroup has no statistically significant difference (P>0.05).

6. Experimental Results of Closed Hypoxia Tolerance in Mice

6.1 Test of Closed Hypoxia Tolerance in Male Mice

TABLE 11 Changes of body weight of male mice before closed hypoxiatolerance test weight (g) Group 1 day 3 days Negative control (equalvolume 15.43 ± 1.14 18.12 ± 1.65 of water) Acetazolamide positive drug15.41 ± 1.08  15.88 ± 1.24** control group(0.16 g/kg) PQQ drug dosegroup I (1.32 mg/kg) 15.46 ± 1.04 17.74 ± 1.30 PQQ drug dose group II(2.64 mg/kg) 15.40 ± 1.03 17.46 ± 1.29 PQQ drug dose group III (5.28mg/kg) 15.51 ± 1.11 17.41 ± 1.23 PQQ drug dose group IV (10.56 mg/kg)15.32 ± 1.10 16.20 ± 1.03 PQQ drug dose group V (21.12 mg/kg) 15.45 ±0.97 17.54 ± 1.14 *p < 0.05, **p < 0.01 VS negative control group

It can be seen from Table 11 that there is no statistically significantdifference in the body weight of the male mice of each group before theexperiment (P>0.05). After administration for 3 days, compared with thecontrol group, the mice in the acetazolamide-positive control group isdecreased (P<0.05), and has no statistically significant difference inbody weight of the PQQ drug dosage groups (P>0.05).

6.2 Confined Hypoxia Tolerance Test in Famale Mice

TABLE 14 Changes of body weight of famale mice before closed hypoxiatolerance test weight (g) Group 1 day 3 days Negative control (equalvolume 20.81 ± 0.70 22.33 ± 0.72 of water) Acetazolamide positive drug20.27 ± 0.90  20.88 ± 1.50* control group(0.16 g/kg) PQQ drug dose groupI (1.32 mg/kg) 20.31 ± 1.29 22.33 ± 1.91 PQQ drug dose group II (2.64mg/kg)  19.83 ± 1.19* 22.22 ± 1.28 PQQ drug dose group III (5.28 mg/kg)20.58 ± 1.07 22.52 ± 1.71 PQQ drug dose group IV (10.56 mg/kg) 20.13 ±1.64 21.92 ± 1.83 PQQ drug dose group V (21.12 mg/kg) 20.19 ± 1.34 22.49± 1.77 *p < 0.05, **p < 0.01 VS negative control group

It can be seen from Table 14 that there is no statistically significantdifference in the body weight of the female mice of each group beforethe experiment (P>0.05). After administration for 3 days, compared withthe control group, the mice weight in the acetazolamide-positive controlgroup is decreased (P<0.05), and has no statistically significantdifference in body weight of the PQQ drug dosage groups (P>0.05).

7. Experimental Results of PQQ Anti-Acute High Altitude Hypoxia Injuryin Rats

7.1 Changes of Rat Body Weight Before the Acute Decompression HypoxiaExperiment

TABLE 17 Changes of rat body weight before the acute decompressionhypoxia experiment Male(g) Female(g) Group 1 day 7 days 1 day 7 daysNormoxia control group (equal 172.3 ± 7.7 200.1 ± 7.8 152.7 ± 8.6 171.9± 9.1 volume of water) Hypoxia model group(equal volume 171.6 ± 6.3 200.8 ± 10.8 153.4 ± 9.2 169.2 ± 7.0 of water) PQQ drug dose group I(0.91 mg/kg) 173.4 ± 7.4 196.4 ± 5.7 154.4 ± 7.2 169.6 ± 3.3 PQQ drugdose group II (1.83 mg/kg) 173.6 ± 5.9 206.8 ± 6.2 153.6 ± 6.9 167.4 ±6.7 PQQ drug dose group III (3.66 mg/kg)  170.8 ± 10.8 198.3 ± 9.0 154.1± 8.6 172.1 ± 2.2 PQQ drug dose group IV (7.31 mg/kg) 169.9 ± 9.9  198.6± 11.6 154.3 ± 7.7 171.1 ± 8.6 PQQ drug dose group V (14.63 mg/kg) 171.6± 10   199.6 ± 12.5 152.7 ± 7.2 166.0 ± 4.1 Acetazolamide positive drug172.4 ± 6.8   189.1 ± 11.8*# 153.4 ± 6.1  163.3 ± 6.76 controlgroup(0.11 g/kg) *p < 0.05, **p < 0.01 VS normoxia control group, #p <0.05, ##p < 0.01 VS hypoxia model group

It can be seen from Table 17 that compared with the normoxia controlgroup and the hypoxic model group, the body weight of theacetazolamide-positive drug control group of male rats is decreasedafter intragastric administration for 7 days, has a statisticallysignificant difference (P<0.05). Other groups has no statisticallysignificant difference (P>0.05). Compared with the normoxia controlgroup and the hypoxic model group, there is no statistically significantdifference in the body weight of female rats before gavage and aftergavage for 7 days (P>0.05).

7.2 Effects of PQQ on Blood Glucose in Rats Exposed to Acute AltitudeHypoxia

TABLE 18 Effects of PQQ on blood glucose in male rats exposed to acutealtitude hypoxia Blood Group sugar(mmol/L) Normoxia control group (equalvolume of water) 8.53 ± 1.54 Hypoxia model group(equal volume of water)8.66 ± 1.78 PQQ drug dose group I (0.91 mg/kg) 7.35 ± 1.94 PQQ drug dosegroup II (1.83 mg/kg) 8.21 ± 1.46 PQQ drug dose group III (3.66 mg/kg)8.97 ± 1.44 PQQ drug dose group IV (7.31 mg/kg) 8.28 ± 1.57 PQQ drugdose group V (14.63 mg/kg) 8.85 ± 2.04 Acetazolamide positive drugcontrol group(0.11 g/kg) 8.87 ± 1.24 *p < 0.05, **p < 0.01 VS normoxiacontrol group, #p < 0.05, ##p < 0.01 VS hypoxia model group

It can be seen from Table 18 that compared with the normoxia controlgroup and the hypoxia model group, there is no statistically significantdifference in blood glucose values of the hypoxia model group and thePQQ each drug dosage group (P>0.05).

TABLE 19 Effects of PQQ on blood glucose in female rats exposed to acutealtitude hypoxia Group Blood sugar(mmol/L) Normoxia control group (equalvolume of water) 8.39 ± 0.44  Hypoxia model group(equal volume of water)6.87 ± 0.54** PQQ drug dose group I (0.91 mg/kg) 8.59 ± 0.48## PQQ drugdose group II (1.83 mg/kg) 8.28 ± 0.84## PQQ drug dose group III (3.66mg/kg) 8.27 ± 0.37## PQQ drug dose group IV (7.31 mg/kg) 7.91 ± 0.65##PQQ drug dose group V (14.63 mg/kg)  7.55 ± 0.48**# Acetazolamidepositive drug control 7.63 ± 0.76*# group(0.11 g/kg) Normoxia PQQ druggroup(3.66 mg/kg) 8.13 ± 0.57  Normoxia acetazolamide group(0.11 g/kg)7.18 ± 0.39** *p < 0.05, **p < 0.01 VS normoxia control group, #p <0.05, ##p < 0.01 VS hypoxia model group

It can be seen from Table 19 that compared with the normoxia controlgroup, the blood glucose values of female rats in the hypoxia modelgroup, the PQQ drug dose group V after hypoxia exposure, theacetazolamide positive drug control group and the normoxia acetazolamidegroup are decreased and have a statistically significant difference(P<0.05). And other groups have no statistically significant differencecompared with the normoxia control group (P>0.05). Compared with thehypoxia model group, the blood glucose values of female rats in the PQQdrug dose groups and the acetazolamide-positive drug control group areincreased, and have statistically significant differences (P<0.05).

7.3 Effects of PQQ on Protein Metabolism in Rats Exposed to AcuteAltitude Hypoxia

TABLE 20 Effects of PQQ on protein metabolism in male rats exposed toacute altitude hypoxia Group albumin (g/L) albumin(g/L) Normoxia controlgroup (equal 51.05 ± 2.50 26.34 ± 0.98  volume of water) Hypoxia modelgroup(equal 52.42 ± 1.47 28.31 ± 1.08** volume of water) PQQ drug dosegroup I (0.91 mg/kg)   42.59 ± 4.24**##  22.55 ± 2.53**## PQQ drug dosegroup II (1.83 mg/kg)  49.30 ± 3.35# 26.14 ± 2.04#  PQQ drug dose groupIII (3.66 mg/kg) 52.71 ± 1.20 28.60 ± 1.12** PQQ drug dose group IV(7.31 mg/kg) 52.55 ± 2.78 28.06 ± 1.31** PQQ drug dose group V (14.63mg/kg) 52.97 ± 1.38 28.38 ± 0.90** Acetazolamide positive drug 53.14 ±2.18 27.87 ± 1.140* control group(0.11 g/kg) *p < 0.05, **p < 0.01 VSnormoxia control group, #p < 0.05, ##p < 0.01 VS hypoxia model group

It can be seen from Table 20 that compared with the normoxia controlgroup, the serum total protein value of male rats for the hypoxia modelgroup and the PQQ drug dose groups (except PQQ drug dose group I) has nostatistically significant difference (P>0.05). Compared with thenormoxia control group, the serum total protein value of PQQ drug dosegroup I is decreased, and has a statistically significant difference(P<0.05). Compared with the hypoxia model group, the total serum proteinvalue of PQQ drug dose group I and PQQ drug dose group II is decreased,and has a statistically significant decrease (P<0.05). There is nostatistically significant difference in other PQQ drug dose groups(P>0.05).

Compared with the normoxia control group, the serum albumin value ofmale rats for the hypoxia model group and PQQ drug dose group I, III,IV, V is increased (P<0.05). Compared with the normoxia control group,PQQ drug dose group II has no statistically significant difference(P>0.05). Compared with the hypoxia model group, the serum albuminvalues of the PQQ drug dose group I and the PQQ drug dose group II aredecreased, and have a statistically significant difference (P<0.05).Other PQQ drug dose groups have no statistically significant difference(P>0.05).

TABLE 21 Effects of PQQ on protein metabolism in famale rats exposed toacute altitude hypoxia Group albumin (g/L) albumin(g/L) Normoxia controlgroup (equal 55.32 ± 2.00 30.28 ± 1.05  volume of water) Hypoxia modelgroup(equal 55.43 ± 1.77 31.40 ± 1.11* volume of water) PQQ drug dosegroup I (0.91 mg/kg) 54.56 ± 1.24 31.03 ± 0.98  PQQ drug dose group II(1.83 mg/kg)  53.04 ± 1.71*#  29.67 ± 0.98## PQQ drug dose group III(3.66 mg/kg)   52.44 ± 1.12**##  29.33 ± 0.62## PQQ drug dose group IV(7.3 l mg/kg) 55.67 ± 1.23 31.49 ± 0.70* PQQ drug dose group V (14.63mg/kg) 53.91 ± 2.09 30.16 ± 1.40  Acetazolamide positive drug 53.90 ±2.23 29.18 ± 1.68# control group(0.11 g/kg) Normoxia PQQ drug group(3.6656.53 ± 1.50 30.87 ± 1.41  mg/kg) Normoxia acetazolamide  59.00 ± 1.59*32.13 ± 0.45* group(0.11 g/kg) *p < 0.05, **p < 0.01 VS normoxia controlgroup, #p < 0.05, ##p < 0.01 VS hypoxia model group

It can be seen from Table 21 that compared with the normoxia controlgroup, the total serum protein values of female rats in the PQQ drugdose group II and III are decreased (P<0.05), and the normoxiaacetazolamide group has a statistically significant increase (P <0.05),there is no statistically significant difference in other groups(P>0.05). Compared with the hypoxia model group, the total serum proteinvalues of the PQQ drug dose group II and III are decreased (P<0.05), butthere is no statistically significant difference in the other groups(P>0.05).

Compared with the normoxia control group, the serum albumin values offemale rats in the hypoxia model group, the PQQ drug dose group IV afterhypoxia exposure, and the normoxia acetazolamide group are increased(P<0.05), and there is no statistically significant difference in theother groups (P>0.05). Compared with the hypoxia model group, the serumalbumin values of the PQQ drug dose group II, the PQQ drug dose groupIII and the acetazolamide positive drug control group are decreased(P<0.05), and there is no statistically significant difference in theother groups (P>0.05).

7.4 Effects of PQQ on Lipid Metabolism in Rats Exposed to Acute AltitudeHypoxia

TABLE 22 Effects of PQQ on lipid metabolism in male rats exposed toacute altitude hypoxia Total High density Low density Triglyceridescholesterol lipoprotein lipoprotein Group (mmol/L) (mmol/L)cholesterol(mmol/L) cholesterol(mmol/L) Normoxia control group (equal1.05 ± 0.29 1.92 ± 0.14 1.36 ± 0.13 0.25 ± 0.03  volume of water)Hypoxia model group(equal 1.08 ± 0.39 1.80 ± 0.14 1.33 ± 0.09 0.18 ±0.03*  volume of water) PQQ drug dose group I (0.91 mg/kg) 1.25 ± 0.64  1.47 ± 0.15**##   1.03 ± 0.09**## 0.16 ± 0.03** PQQ drug dose group II(1.83 mg/kg) 1.06 ± 0.35  1.71 ± 0.90** 1.23 ± 0.11 0.20 ± 0.02** PQQdrug dose group III (3.66 mg/kg) 1.36 ± 0.58 1.80 ± 0.16 1.28 ± 0.090.19 ± 0.04** PQQ drug dose group IV (7.31 mg/kg) 1.35 ± 0.36  1.69 ±0.10**  1.23 ± 0.10*# 0.16 ± 0.02** PQQ drug dose group V (14.63 mg/kg)1.40 ± 0.74  1.95 ± 0.15# 1.44 ± 0.15 0.19 ± 0.03** Acetazolamidepositive drug 1.05 ± 0.49 1.88 ± 0.21 1.39 ± 0.14 0.21 ± 0.05  controlgroup(0.11 g/kg) *p < 0.05, **p < 0.01 VS normoxia control group, #p <0.05, ##p < 0.01 VS hypoxia model group

It can be seen from Table 22 that compared with the normoxia controlgroup and hypoxia model group, the serum triglyceride content of malerats in each drug intervention group has no statistically significantdifference (P>0.05).

Compared with the normoxia control group, the total serum cholesterolvalues of male rats in the PQQ drug dose group I, the PQQ drug dosegroup II and the PQQ drug dose group IV are decreased (P<0.05), andthere is no statistically significant difference in the other groups(P>0.05). Compared with the hypoxia model group, the total serumcholesterol value of male rats in the PQQ drug dose group I is decreased(P<0.05), and the total serum cholesterol value of the PQQ drug dosegroup V is increased (P<0.05), and there is no statistically significantdifference in the other groups (P>0.05).

Compared with the normoxia control group, the serum high-densitylipoprotein cholesterol values of male rats in PQQ drug dose group I andthe PQQ drug dose group IV are decreased (P<0.05), and there is nostatistically significant difference in the other groups (P>0.05).Compared with the hypoxia model group, the serum HDL cholesterol valuesof male rats in PQQ drug dose group I and PQQ drug dose group IV aredecreased (P<0.05), and there is no statistically significant differencein the other groups (P>0.05)).

Compared with the normoxia control group, the serum low-densitylipoprotein cholesterol values of male rats in each group are reduced,except for the acetazolamide positive drug control group, the othergroups have statistically significant differences (P<0.05). Comparingwith hypoxia model group, the serum low-density lipoprotein cholesterolvalues of male rats in each drug treatment group has no statisticallysignificant difference (P>0.05).

TABLE 23 the effect of PQQ on lipid metabolism in famale rats exposed toacute altitude hypoxia Total High density Low density cholesterollipoprotein lipoprotein Group (mmol/L) cholesterol(mmol/L)cholesterol(mmol/L) Normoxia control group 1.89 ± 0.11  1.35 ± 0.07 0.16± 0.13  (equal volume of water) Hypoxia model group(equal 1.67 ± 0.13**1.27 ± 0.10 0.11 ± 0.02** volume of water) PQQ drug dose group 1.69 ±0.11** 1.30 ± 0.07 0.12 ± 0.01** I(0.91 mg/kg) PQQ drug dose group 1.56± 0.17**  1.18 ± 0.14** 0.10 ± 0.02** II(1.83 mg/kg) PQQ drug dose group 1.47 ± 0.11**##   1.14 ± 0.10**# 0.10 ± 0.02** III(3.66 mg/kg) PQQ drugdose group 1.69 ± 0.09** 1.27 ± 0.09 0.10 ± 0.02** IV(7.31 mg/kg) PQQdrug dose group 1.64 ± 0.13** 1.28 ± 0.11 0.11 ± 0.02** V(14.63 mg/kg)Acetazolamide positive 2.02 ± 0.20##   1.55 ± 0.19*## 0.17 ± 0.04## drugcontrol group(0.11 g/kg) Normoxia PQQ drug 1.87 ± 0.10  1.39 ± 0.10 0.14± 0.03  group(3.66 mg/kg) Normoxia acetazolamide 2.14 ± 0.10**  1.67 ±0.07** 0.16 ± 0.02  group(0.11 g/kg) *p < 0.05, **p < 0.01 VS normoxiacontrol group, #p < 0.05, ##p < 0.01 VS hypoxia model group

It can be seen from Table 23 that compared with the normoxia controlgroup, the total serum cholesterol values of female rats in the hypoxiamodel group and the PQQ drug dosage groups after hypoxia exposure aredecreased (P<0.05), and the acetazolamide positive drug control groupafter hypoxia exposure has no statistically significant difference,while the serum total cholesterol value of the normoxazinamide group isincreased, and there is a statistically significant difference (P<0.05).The acetazolamide positive drug control group and the normoxia PQQ druggroup have no statistically significant difference (P>0.05). Comparedwith the hypoxia model group, the total serum cholesterol value offemale rats in the PQQ drug dose group III is decreased (P<0.05), andthe total serum cholesterol value of the acetazolamide-positive drugcontrol group is increased (P<0.05), the other groups have nostatistically significant difference (P>0.05).

Compared with the normoxia control group, female rats in PQQ drug dosegroup II and PQQ drug dose group III have lower serum HDL cholesterolvalues (P<0.05), the serum HDL cholesterol values of the acetazolamidepositive drug control group and the normoxazinamide group are increased(P<0.05), and the other groups have no statistically significantdifference (P>0.05). Compared with the hypoxia model group, the serumHDL cholesterol value of female rats in the PQQ drug dose group III isdecreased (P<0.05), and the serum HDL cholesterol value of theacetazolamide positive drug control group is increased (P<0.05), and theother groups have no statistically significant difference (P>0.05).

Compared with the normoxia control group, the serum low-densitylipoprotein cholesterol values of female rats in the hypoxia model groupand the drug intervention group after hypoxia exposure are decreased(P<0.05), and the serum low-density lipoprotein cholesterol values inthe normoxia PQQ drug group and the acetazolamide group have nostatistically significant difference (P>0.05). Compared with the hypoxiamodel group, the LDL cholesterol value of female rats in theacetazolamide positive drug control group is increased (P<0.05), andthere is no statistically significant difference in the other groups(P>0.05).

7.5 Effects of PQQ on Liver Function of Rats Exposed to Acute AltitudeHypoxia

TABLE 24 Effects of PQQ on liver function of male rats exposed to acutealtitude hypoxia Glutamic-pyruvic Glutamic oxalacetic Total Grouptransaminase (U) transaminase (U) bilirubin(μmol/L) Normoxia controlgroup 37.11 ± 6.01 82.13 ± 15.34 0.46 ± 0.24 (equal volume of water)Hypoxia model group(equal 42.33 ± 9.80 96.44 ± 13.81 0.59 ± 0.24 volumeof water) PQQ drug dose group 36.63 ± 8.30  79.17 ± 15.66# 0.51 ± 0.12I(0.91 mg/kg) PQQ drug dose group 40.63 ± 5.18 85.80 ± 13.80 0.59 ± 0.12II(1.83 mg/kg) PQQ drug dose group 42.50 ± 4.93 99.00 ± 15.52 0.60 ±0.15 III(3.66 mg/kg) PQQ drug dose group 43.13 ± 8.92 94.40 ± 12.28 0.46± 0.15 IV(7.31 mg/kg) PQQ drug dose group  48.25 ± 8.86*  109.00 ±11.68** 0.53 ± 0.15 V(14.63 mg/kg) Acetazolamide positive  44.00 ± 3.56* 77.57 ± 6.80## 0.15 ± 0.16 drug control group(0.11 g/kg) *p < 0.05, **p< 0.01 VS normoxia control group, #p < 0.05, ##p < 0.01 VS hypoxia modelgroup

It can be seen from Table 24 that compared with the normoxia controlgroup, the serum glutamic-pyruvic transaminase activity of male rats inthe PQQ drug dose group V and the acetazolamide positive drug controlgroup is increased (P<0.05), and the other groups have no statisticallysignificant difference (P>0.05). Compared with the hypoxia model group,there is no statistically significant difference in the alanineaminotransferase activity of male rats in each treatment group (P>0.05).

Compared with the normoxia control group, the serum glutamic oxalacetictransaminase activity of male rats in PQQ drug dose group V is increased(P<0.05), and there is no statistically significant difference in theother groups (P>0.05). Compared with the hypoxia model group, the serumglutamic oxalacetic transaminase activity of male rats in the PQQ drugdose group I and the acetazolamide positive drug control groupdecreased, and there was a statistically significant difference(P<0.05), while the other groups had no statistically significantdifference (P>0.05).

Compared with the normoxia control group and hypoxia model group, thereis no statistically significant difference in total bilirubin of malerats in each group (P>0.05).

TABLE 25 Effect of PQQ on liver function of famale rats exposed to acutealtitude hypoxia Glutamic- Glutamic pyruvic oxalacetic transaminasetransaminase Group (U) (U) Normoxia control group 35.89 ± 9.61 95.00 ±15.72 (equal volume of water) Hypoxia model group(equal 33.33 ± 5.17 78.00 ± 17.02* volume of water) PQQ drug dose group 29.86 ± 4.30 80.71± 12.49 I(0.91 mg/kg) PQQ drug dose group 27.86 ± 6.28 84.71 ± 18.97II(1.83 mg/kg) PQQ drug dose group 32.57 ± 5.35 82.29 ± 17.75 III(3.66mg/kg) PQQ drug dose group 32.57 ± 6.37 79.29 ± 16.06 IV(7.31 mg/kg) PQQdrug dose group 36.57 ± 8.52 83.00 ± 20.18 V(14.63 mg/kg) Acetazolamidepositive 28.40 ± 2.30  73.20 ± 11.19* drug control group(0.11 g/kg)Normoxia PQQ drug 37.14 ± 4.45  120.29 ± 11.90** group(3.66 mg/kg)Normoxia acetazolamide  41.67 ± 10.97 102.33 ± 11.02  group(0.11 g/kg)*p < 0.05, **p < 0.01 VS normoxia control group, #p < 0.05, ##p < 0.01VS hypoxia model group

It can be seen from Table 25 that compared with the normoxia controlgroup and the hypoxia model group, there is no statistically significantdifference in the glutamic-pyruvic transaminase activity of female ratsin each group (P>0.05).

Compared with the normoxia control group, the serum glutamic oxalacetictransaminase activity of female rats in the hypoxia model group and theacetazolamide positive drug control group decreased (P<0.05), and thenormoxia PQQ drug group is increased (P<0.05). Compared with the hypoxiamodel group, there is no statistically significant difference in serumglutamic oxalacetic transaminase activity in each drug interventiongroup (P>0.05).

7.6 Effects of PQQ on Renal Function in Rats Exposed to Acute AltitudeHypoxia

TABLE 26 Effects of PQQ on renal function in male rats exposed to acutealtitude hypoxia Serum urea Uric Group nitrogen (mmol/L)Creatinine(μmol/L) acid (μmol/L) Normoxia control group 5.37 ± 0.6222.43 ± 2.06 161.86 ± 9.21    (equal volume of water) Hypoxia model 6.10± 1.08 22.60 ± 5.51 180.33 ± 17.30*   group(equal volume of water) PQQdrug dose group 5.13 ± 0.75  18.44 ± 1.46** 134.25 ± 19.08**## I(0.91mg/kg) PQQ drug dose group 5.44 ± 1.13 21.59 ± 3.31 142.60 ± 10.78**##II(1.83 mg/kg) PQQ drug dose group 6.37 ± 1.64 21.90 ± 2.88 171.38 ±14.92   III(3.66 mg/kg) PQQ drug dose group 5.91 ± 0.86 22.40 ± 1.53202.16 ± 17.13**#  IV(7.31 mg/kg) PQQ drug dose group 6.23 ± 1.36 22.49± 3.00 182.22 ± 15.80**  V(14.63 mg/kg) Acetazolamide positive   7.99 ±1.03**##  25.01 ± 2.48*  81.86 ± 11.05**## drug control group (0.11g/kg) *p < 0.05, **p < 0.01 VS normoxia control group, #p < 0.05, ##p <0.01 VS hypoxia model group

It can be seen from Table 26 that compared with the normoxia controlgroup and the hypoxia model group, the serum urea nitrogen content ofthe male rats in the acetazolamide positive drug control group isincreased (P<0.05), and has no statistics significant difference in theother groups (P>0.05).

Compared with the normoxia control group, the serum creatinine value ofmale rats in the PQQ drug dose group I is decreased (P<0.05), and theserum creatinine value of the acetazolamide positive drug control groupis increased (P<0.05), but has no statistics significant difference inthe other groups (P>0.05). Compared with the hypoxia model group, thereis no statistically significant difference in each group (P>0.05).

Compared with the normoxia control group, the serum uric acid levels ofmale rats in hypoxia model group, PQQ drug dose group IV and PQQ drugdose group V are increased (P<0.05). The serum uric acid levels of thePQQ drug dose group I, the drug dose group II and the acetazolamidepositive drug control group are decreased, and there is a statisticallysignificant difference (P<0.05). There is no statistically significantdifference in the PQQ drug dose group III (P>0.05). Compared with thehypoxia model group, the serum uric acid levels of male rats in the PQQdrug dose group I, drug dose group II and the acetazolamide positivedrug control group are decreased, and there is a statisticallysignificant difference (P<0.05). The serum uric acid level in the PQQdrugs dose group IV is increased (P<0.05), and there is no statisticallysignificant difference in the other groups (P>0.05).

TABLE 27 Effects of PQQ on renal function in female rats exposed toacute altitude hypoxia Serum urea Uric Group nitrogen (mmol/L)Creatinine(μmol/L) acid (μmol/L) Normoxia control 5.76 ± 0.74 17.81 ±0.90  165.89 ± 19.35 group (equal volume of water) Hypoxia model 6.10 ±0.64 14.88 ± 1.46**  147.78 ± 12.38* group(equal volume of water) PQQdrug dose group  6.85 ± 0.90* 14.67 ± 1.46**  163.43 ± 12.51# I(0.91mg/kg) PQQ drug dose group 5.98 ± 0.62 14.23 ± 1.90** 152.71 ± 16.58II(1.83 mg/kg) PQQ drug dose group 5.79 ± 0.62  12.71 ± 1.98**# 151.14 ±18.48 III(3.66 mg/kg) PQQ drug dose group 6.00 ± 0.98 16.06 ± 1.19**152.43 ± 25.28 IV(7.31 mg/kg) PQQ drug dose group 5.86 ± 0.54 13.51 ±1.33** 155.33 ± 21.56 V(14.63 mg/kg) Acetazolamide   8.02 ± 1.05**##18.78 ± 1.96##   77.80 ± 17.31*## positive drug control group(0.11 g/kg)Normoxia PQQ drug 6.23 ± 0.36 19.37 ± 4.32   193.57 ± 20.80* group(3.66mg/kg) Normoxia  7.86 ± 0.49** 19.67 ± 0.32**   82.00 ± 15.10**acetazolamide group(0.11 g/kg) *p < 0.05, **p < 0.01 VS normoxia controlgroup, #p < 0.05, ##p < 0.01 VS hypoxia model group

It can be seen from Table 27 that compared with the normoxia controlgroup, the serum urea nitrogen levels of female rats in the PQQ drugdose group I, the acetazolamide positive drug control group and thenormoxazolamide group after hypoxia exposure are increased (P <0.05),there is no statistically significant difference in other groups(P>0.05). Compared with the hypoxia model group, the serum urea nitrogenlevel of female rats in the acetazolamide positive drug control group isstatistically significantly increased (P<0.05), and there is nostatistically significant difference in the other groups (P >0.05).

Compared with the normoxia control group, the serum creatinine values offemale rats in the hypoxia model group and the PQQ drug dose groupsafter hypoxia exposure are decreased, and there is a statisticallysignificant difference (P<0.05). The creatinine value in theacetazolamide positive drug control group is increased (P<0.05), andthere is no statistically significant difference in other groups(P>0.05). Compared with the hypoxia model group, the serum creatininevalue of female rats in the PQQ drug dose group III is decreased, andthere is a statistically significant difference (P<0.05), the serumcreatinine value of the acetazolamide positive drug control group isincreased (P<0.05), there is no statistically significant difference inother groups (P>0.05).

Compared with the normoxia control group, the serum uric acid levels inthe hypoxia model group, the acetazolamide positive drug control groupand the normoxazolamide group are decreased serum decreased, and thereis a statistically significant difference (P<0.05). The serum uric acidlevel in the PQQ drug group is increased (P<0.05), and there is nostatistically significant difference in the other groups (P>0.05).Compared with the hypoxia model group, the serum uric acid level of malerats in the acetazolamide positive drug control group is decreased(P<0.05), and the serum uric acid level of PQQ drug dose group I isslightly increased (P<0.05), and the other groups have no statisticallysignificant difference (P>0.05).

7.7 Effects of PQQ on Myocardial Enzyme Activity in Rats Exposed toAcute Altitude Hypoxia

TABLE 28 Effects of PQQ on myocardial enzyme activity in male ratsexposed to acute altitude hypoxia Lactate Creatine α-hydroxybutyrateGroup dehydrogenase (U/L) Kinase (U/L) dehydrogenase(U/L) Normoxiacontrol group 532.00 ± 315.79 524.11 ± 222.26 218.67 ± 129.36 (equalvolume of water) Hypoxia model 449.22 ± 261.12 396.67 ± 172.01 184.00 ±105.80 group(equal volume of water) PQQ drug dose group 463.38 ± 364.37443.63 ± 260.18 218.00 ± 173.09 I(0.91 mg/kg) PQQ drug dose group 650.13± 573.72 544.63 ± 418.71 286.75 ± 260.98 II(1.83 mg/kg) PQQ drug dosegroup 588.13 ± 360.36 544.50 ± 243.30 256.63 ± 154.55 III(3.66 mg/kg)PQQ drug dose group 767.38 ± 546.88 640.25 ± 333.16 325.63 ± 238.56IV(7.31 mg/kg) PQQ drug dose group 510.44 ± 275.48 510.89 ± 240.61218.67 ± 118.08 V(14.63 mg/kg) Acetazolamide positive 303.86 ± 174.67352.43 ± 138.11 126.29 ± 67.51  drug control group(0.11 g/kg) *p < 0.05,**p < 0.01 VS normoxia control group, #p < 0.05, ##p < 0.01 VS hypoxiamodel group

It can be seen from Table 28 that compared with the normoxia controlgroup and the hypoxia model group, there is no statistically significantdifference in the lactate dehydrogenase of male rats in each group(P>0.05).

Compared with the normoxia control group and hypoxia model group, thereis no statistically significant difference in the creatine kinase ofmale rats in each group (P>0.05).

Compared with the normoxia control group and hypoxia model group, thereis no statistically significant difference in the α-hydroxybutyratedehydrogenase of male rats in each group (P>0.05).

TABLE 29 Effects of PQQ on myocardial enzyme activity in female ratsexposed to acute altitude Lactate Creatine α-hydroxybutyrate Groupdehydrogenase (U/L) Kinase (U/L) dehydrogenase(U/L) Normoxia control774.78 ± 378.72 712.89 ± 166.80  376.11 ± 132.67 group (equal volume ofwater) Hypoxia model 494.11 ± 333.54 437.11 ± 291.80*  209.11 ± 151.30*group(equal volume of water) PQQ drug dose group 627.43 ± 253.66 505.43± 202.03* 270.28 ± 111.79 I(0.91 mg/kg) PQQ drug dose group 650.00 ±338.13 508.57 ± 235.83  286.71 ± 154.38 II(1.83 mg/kg) PQQ drug dosegroup 544.14 ± 314.26 459.14 ± 239.34* 233.43 ± 147.72 III(3.66 mg/kg)PQQ drug dose group 499.71 ± 320.46 454.86 ± 241.51*  210.14 ± 140.24*IV(7.31 mg/kg) PQQ drug dose group 496.86 ± 259.65 439.86 ± 222.18* 208.86 ± 112.12* V(14.63 mg/kg) Acetazolamide 534.00 ± 179.23 503.40 ±137.62* 230.20 ± 75.49* positive drug control group(0.11 g/kg) NormoxiaPQQ drug  1199.14 ± 204.93** 1024.00 ± 313.62*  537.29 ± 92.21*group(3.66 mg/kg) Normoxia 998.67 ± 285.56 697.67 ± 222.15  430.33 ±134.10 acetazolamide group(0.11 g/kg) *p < 0.05, **p < 0.01 VS normoxiacontrol group, #p < 0.05, ##p < 0.01 VS hypoxia model group

It can be seen from Table 29 that compared with the normoxia controlgroup, the lactate dehydrogenase activity of the normoxia PQQ drug groupis increased (P<0.05), and there is no statistically significantdifference in the other groups (P>0.05). Compared with the hypoxia modelgroup, there is no statistically significant difference in each group(P>0.05).

Compared with the normoxia control group, the serum creatine kinaseactivity of female rats in the hypoxia model group and the drug groupafter each hypoxia exposure is decreased (P<0.05), and the serumcreatine kinase activity of the normoxia PQQ drug group is increased (P<0.05), there is no statistically significant difference in other groups(P>0.05). Compared with the hypoxia model group, there is nostatistically significant difference in each group (P>0.05).

Compared with the normoxia control group, the serum α-hydroxybutyratedehydrogenase activity of female rats in the hypoxia model group, thedrug dose group IV, the drug dose group V and the positive acetazolamidecontrol group after hypoxia exposure is decreased, there isstatistically significant difference (P<0.05). The serumα-hydroxybutyrate dehydrogenase activity in the normoxia PQQ drug groupis increased (P<0.05), and there is no statistically significantdifference in other groups (P>0.05). Compared with the hypoxia modelgroup, there is no statistically significant difference in each group(P>0.05).

7.8 Effects of PQQ on Serum Homocysteine in Rats Exposed to AcuteAltitude Hypoxia

TABLE 30 Effects of PQQ on serum homocysteine in male rats exposed toacute altitude hypoxia Serum homocysteine Group (μmol/L) Normoxiacontrol group (equal 9.09 ± 2.29 volume of water) Hypoxia modelgroup(equal 11.98 ± 2.28* volume of water) PQQ drug dose group I(0.91mg/kg) 11.18 ± 2.09  PQQ drug dose group II(1.83 mg/kg) 13.24 ± 3.87*PQQ drug dose group III(3.66 mg/kg)  13.65 ± 3.24** PQQ drug dose groupIV(7.31 mg/kg) 11.48 ± 2.36  PQQ drug dose group V(14.63 mg/kg)  12.78 ±2.87** Acetazolamide positive drug 11.13 ± 1.67  control group(0.11g/kg) *p < 0.05, **p < 0.01 VS normoxia control group, #p < 0.05, ##p <0.01 VS hypoxia model group

It can be seen from Table 30 that compared with the normoxia controlgroup, the serum homocysteine levels of male rats in the hypoxia modelgroup, PQQ drug dose group II, drug dose group III and drug dose group Vare increased (P<0.05), the other groups have no statisticallysignificant differences (P>0.05). Compared with the hypoxia model group,there is no statistically significant difference in each drugintervention group (P>0.05).

TABLE 31 Effects of PQQ on serum homocysteine in female rats exposed toacute altitude hypoxia Serum homocysteine Group (μmol/L) Normoxiacontrol group (equal volume of water) 9.82 ± 1.29 Hypoxia modelgroup(equal volume of water) 8.14 ± 1.6* PQQ drug dose group I(0.91mg/kg) 9.43 ± 1.4  PQQ drug dose group II(1.83 mg/kg) 10.66 ± 2.13# PQQdrug dose group III(3.66 mg/kg) 9.63 ± 1.97 PQQ drug dose group IV(7.31mg/kg)  8.6 ± 1.72 PQQ drug dose group V(14.63 mg/kg)  8.11 ± 1.37*Acetazolamide positive drug control 9.54 ± 0.98 group(0.11 g/kg)Normoxia PQQ drug group(3.66 mg/kg) 9.76 ± 1.16 Normoxia acetazolamidegroup(0.11 g/kg) 9.33 ± 1.16 *p < 0.05, **p < 0.01 VS normoxia controlgroup, #p < 0.05, ##p < 0.01 VS hypoxia model group

It can be seen from Table 31 that compared with the normoxia controlgroup, the serum homocysteine levels of female rats in the hypoxia modelgroup and the PQQ drug dose group V after hypoxia exposure are decreased(P<0.05), there is no statistically significant difference in each drugintervention group(P>0.05). Compared with the hypoxia model group, theserum homocysteine level of female rats in the PQQ drug dose group IIafter hypoxia exposure is increased (P<0.05), and there is nostatistically significant difference in the other groups (P>0.05).

7.9 Effects of PQQ on Endothelial Function in Rats Exposed to AcuteAltitude Hypoxia

TABLE 32 Effects of PQQ on endothelial function in male rats exposed toacute altitude hypoxia Endothelin-1 Nitric oxide Group (ng/mL) (μmol /L)Normoxia control group (equal 45.25 ± 3.11 5.39 ± 2.3  volume of water)Hypoxia model group(equal 46.14 ± 3.20 5.33 ± 1.42 volume of water) PQQdrug dose group I(0.91 mg/kg) 45.35 ± 4.24 5.28 ± 0.71 PQQ drug dosegroup II(1.83 mg/kg)  42.59 ± 1.45# 5.15 ± 2.11 PQQ drug dose groupIII(3.66 mg/kg) 48.14 ± 3.13 5.35 ± 1.35 PQQ drug dose group IV(7.31mg/kg) 43.60 ± 0.94 6.20 ± 2.49 PQQ drug dose group V(14.63 mg/kg) 42.45± 3.84 6.46 ± 1.44 Acetazolamide positive drug 42.41 ± 0.7#  3.52 ±1.25# control group(0.11 g/kg) *p < 0.05, **p < 0.01 VS normoxia controlgroup, #p < 0.05, ##p < 0.01 VS hypoxia model group

It can be seen from Table 32 that compared with the normoxia controlgroup, there is no statistically significant difference in the serumendothelin-1 content of the hypoxia model group and each drugintervention group(P>0.05). Compared with the hypoxia model group, theserum endothelin-1 levels in the PQQ drug dose group II and theacetazolamide positive drug control group are decreased (P<0.05), andthere is no statistically significant difference in the other groups(P>0.05).

Compared with the normoxia control group, there is no statisticallysignificant difference in serum nitric oxide content of the hypoxiamodel group and the drug intervention groups (P>0.05). Compared with thehypoxia model group, the serum nitric oxide content of the acetazolamidepositive drug control group is decreased (P<0.05), and there is nostatistically significant difference in the other groups (P>0.05).

TABLE 33 Effects of PQQ on endothelial function in female rats exposedto acute altitude hypoxia Endothelin-1 Nitric oxide Group (ng/mL) (μmol/L) Normoxia control group 55.50 ± 4.69   5.74 ± 1.49 (equal volume ofwater) Hypoxia model group(equal 49.59 ± 5.92*   6.03 ± 2.28 volume ofwater) PQQ drug dose group 64.75 ± 2.72**##   3.50 ± 1.24**# I(0.91mg/kg) PQQ drug dose group 63.21 ± 4.33**## 4.47 ± 1.35 II(1.83 mg/kg)PQQ drug dose group 68.58 ± 5.38**## 6.19 ± 2.06 III(3.66 mg/kg) PQQdrug dose group 65.44 ± 14.06*#  5.92 ± 2.31 IV(7.31 mg/kg) PQQ drugdose group 65.26 ± 6.60**## 4.62 ± 3.25 V(14.63 mg/kg) Acetazolamidepositive drug 55.66 ± 6.39   4.96 ± 3.13 control group(0.11 g/kg)Normoxia PQQ drug 47.50 ± 7.31*   5.01 ± 1.57 group(3.66 mg/kg) Normoxiaacetazolamide 36.18 ± 2.31**  4.08 ± 0.88 group(0.11 g/kg) *p < 0.05,**p < 0.01 VS normoxia control group, #p < 0.05, ##p < 0.01 VS hypoxiamodel group

It can be seen from Table 33 that compared with the normoxia controlgroup, the serum endothelin-1 levels of female rats in the hypoxia modelgroup, the normoxia PQQ drug group and the normoxazinamide group aredecreased (P<0.05), the levels of serum endothelin-1 in each PQQ drugdose group after hypoxia exposure are increased, and has statisticallysignificant (P<0.05), and there is no statistically significantdifference in the acetazolamide positive drug control group (P>0.05).Compared with the hypoxia model group, the serum endothelin-1 levels inthe PQQ medication group after hypoxia exposure are increased (P<0.05),and there is no statistically significant difference in theacetazolamide positive control group (P>0.05).

Compared with the normoxia control group and hypoxia model group, theserum nitric oxide content of female rats in the PQQ drug dose group Iafter hypoxia exposure is decreased (P<0.05), and there is nostatistically significant difference in the other groups (P >0.05).

7.10 Effects of PQQ on Oxidative Stress Indexes of Rats with AcuteAltitude Hypoxia Injury

TABLE 34 Effect of PQQ on oxidative stress indexes of male rats withacute altitude hypoxia injury Superoxide Total Malonaldehyde Groupdismutase (U/ml) antioxidants (U/ml) (nmol/L) Normoxia control group176.02 ± 2.97   2.48 ± 0.79 2.09 ± 1.27 (equal volume of water) Hypoxiamodel 173.43 ± 4.44   2.05 ± 0.68 3.29 ± 1.59 group(equal volume ofwater) PQQ drug dose group 196.26 ± 4.15**## 3.17 ± 1.40 2.79 ± 0.62I(0.91 mg/kg) PQQ drug dose group 193.38 ± 4.53**## 2.77 ± 1.10 2.89 ±1.09 II(1.83 mg/kg) PQQ drug dose group 189.59 ± 5.46**##  3.81 ± 0.97*# 3.9 ± 1.39 III(3.66 mg/kg) PQQ drug dose group 186.20 ± 6.32**## 3.62 ±1.94 3.15 ± 0.99 IV(7.31 mg/kg) PQQ drug dose group 179.58 ± 6.32   1.49± 2.30  3.59 ± 1.15* V(14.63 mg/kg) Acetazolamide positive 182.51 ±4.46*##  1.23 ± 1.93 3.24 ± 1.52 drug control group(0.11 g/kg) *p <0.05, **p < 0.01 VS normoxia control group, #p < 0.05, ##p < 0.01 VShypoxia model group

It can be seen from Table 34 that compared with the normoxia controlgroup and the hypoxia model group, the serum superoxide dismutaseactivity of male rats in the PQQ drug dose group I, II, III, and IV andthe acetazolamide positive drug control group is increased (P<0.05),there is no statistically significant difference in drug dose group V(P>0.05).

Compared with the normoxia control group and the hypoxia model group,the serum total antioxidant value of male rats in the PQQ drug dosegroup III is increased (P<0.05), and there is no statisticallysignificant difference in the other groups (P>0.05).

Compared with the normoxia control group, the serum malondialdehydevalue of male rats in the PQQ drug dose group V is increased (P<0.05),and there is no statistically significant difference in the other groups(P>0.05). Compared with the hypoxia model group, there is nostatistically significant difference in each group (P>0.05).

TABLE 35 Effects of PQQ on oxidative stress indexes of female rats withacute altitude hypoxia injury Superoxide Total Endo Group dismutase(U/ml) antioxidants (U/ml) Dialdehyde(nmol/L) Normoxia control 53.32 ±2.39 11.19 ± 0.71 13.09 ± 0.85 group (equal volume of water) Hypoxiamodel 52.84 ± 2.55 10.66 ± 0.93 13.01 ± 0.79 group(equal volume ofwater) PQQ drug dose   66.11 ± 4.18**## 10.52 ± 1.08  15.07 ± 1.91*#group I(0.91 mg/kg) PQQ drug dose   60.79 ± 2.56**##  10.06 ± 0.77**13.96 ± 1.33 group II(1.83 mg/kg) PQQ drug dose  56.82 ± 3.80*# 10.84 ±0.47 13.73 ± 0.27 group III(3.66 mg/kg) PQQ drug dose  56.65 ± 2.97*# 10.37 ± 0.75* 14.14 ± 2.68 group IV(7.31 mg/kg) PQQ drug dose  56.16 ±3.64# 10.59 ± 1.65   14.81 ± 1.37**# group V(14.63 mg/kg) Acetazolamide 57.11 ± 3.40*# 10.36 ± 0.81 13.09 ± 2.13 positive drug controlgroup(0.11 g/kg) Normoxia PQQ drug 52.21 ± 1.23 11.28 ± 0.83  14.39 ±0.85** group(3.66 mg/kg) Normoxia 50.88 ± 3.34 10.31 ± 0.20 14.12 ± 0.32acetazolamide group(0.11 g/kg) *p < 0.05, **p < 0.01 VS normoxia controlgroup, #p < 0.05, ##p < 0.01 VS hypoxia model group

It can be seen from Table 35 that compared with the normoxia controlgroup, the serum superoxide dismutase activity of female rats in the PQQdrug dose group I, II, III, and IV and the acetazolamide positive drugcontrol group after hypoxia exposure is increased (P<0.05), there is nostatistically significant difference in the drug dose group V, thenormoxia PQQ drug group and the normoxia acetazolamide group (P>0.05).Compared with the hypoxia model group, the superoxide dismutase activityof female rats in each PQQ drug dose group after hypoxia exposure isincreased, and there is a statistically significant difference (P<0.05).

Compared with the normoxia control group, the total antioxidants valueof female rats in PQQ drug dose group II and drug dose group IV afterhypoxia exposure is increased statistically (P<0.05), but has nostatistics significant difference in other groups (P>0.05). Comparedwith the hypoxia model group, there is no statistically significantdifference in each group (P>0.05).

Compared with the normoxia control group, the serum malondialdehydelevel of female rats in the PQQ drug dose group I, drug dose group V andthe normoxia PQQ drug group after hypoxia exposure is increasedsignificantly (P<0.05) , the other groups had no statisticallysignificant difference (P>0.05). Compared with the hypoxia model group,the serum malondialdehyde value of female rats in PQQ drug dose group Iand drug dose group V is increased (P<0.05), and there is nostatistically significant difference in other groups (P>0.05) .

7.11 Effects of PQQ on Serum Energy Metabolism Indexes in Rats withAcute Altitude Hypoxia Injury

TABLE 36 Effects of PQQ on serum energy metabolism indexes in male ratswith acute altitude hypoxia injury ATP Lactic acid Group (g/ml) (ng/L)Normoxia control group (equal  168.9 ± 16.37 171.99 ± 11.17 volume ofwater) Hypoxia model group(equal  180.5 ± 17.85 182.06 ± 17.02 volume ofwater) PQQ drug dose group I(0.91 mg/kg) 185.81 ± 28.52 188.70 ± 29.68PQQ drug dose group II(1.83 mg/kg) 184.99 ± 17.98 177.33 ± 19.55 PQQdrug dose group III(3.66 mg/kg) 188.84 ± 24.99 189.12 ± 24.64 PQQ drugdose group IV(7.31 mg/kg) 178.23 ± 9.97  172.64 ± 12.25 PQQ drug dosegroup V(14.63 mg/kg) 188.83 ± 22.67 180.81 ± 24.64 Acetazolamidepositive drug 161.13 ± 15.39 161.46 ± 6.94# control group(0.11 g/kg) *p< 0.05, **p < 0.01 VS normoxia control group, #p < 0.05, ##p < 0.01 VShypoxia model group

It can be seen from Table 36 that compared with the normoxia controlgroup and hypoxia model group, the serum ATP content of male rats ineach group has no statistically significant difference (P>0.05).

Compared with the normoxia control group, the serum lactic acid contentof male rats in each group has no statistically significant difference(P>0.05). Compared with the hypoxia model group, the serum lactic acidcontent of male rats in the acetazolamide positive drug control group isdecreased (P<0.05), and there is no statistically significant differencein the other groups (P>0.05).

TABLE 37 Effect of PQQ on serum energy metabolism indexes in female ratswith acute altitude hypoxia injury ATP Lactic acid Group (g/ml) (ng/L)Normoxia control group (equal 166.83 ± 19.73 174.08 ± 20.52   volume ofwater) Hypoxia model group(equal 166.05 ± 23.55 116.1 ± 20.02**  volumeof water) PQQ drug dose group I(0.91 mg/kg)   202.36 ± 8.59**## 222.06 ±12.56**## PQQ drug dose group II(1.83 mg/kg)   200.55 ± 20.92**## 221.04± 14.36**## PQQ drug dose group III(3.66 mg/kg)   212.82 ± 8.82**##242.8 ± 8.13**## PQQ drug dose group IV(7.31 mg/kg)   210.73 ± 10.57**##196.41 ± 11.86*##  PQQ drug dose group V(14.63 mg/kg)   197.73 ±17.99**# 173.09 ± 24.20##  Acetazolamide positive drug 183.19 ± 24.74132.16 ± 10.42**  control group(0.11 g/kg) Normoxia PQQ drug group(3.66149.69 ± 24.29 116.73 ± 13.32**  mg/kg) Normoxia acetazolamide  138.28 ±13.97* 100.54 ± 7.13**   group(0.11 g/kg) *p < 0.05, **p < 0.01 VSnormoxia control group, #p < 0.05, ##p < 0.01 VS hypoxia model group

It can be seen from Table 37 that compared with the normoxia controlgroup, the serum ATP content of the each PQQ drug dose group afterhypoxia exposure is increased, and there is a statistically significantdifference (P<0.05). Compared with the hypoxia model group, the serumATP content of the each PQQ drug dose group after hypoxia exposure isincreased(P<0.05), and there is no statistically significant differencein the acetazolamide positive drug control group (P>0.05). The serum ATPcontent of female rats in the normoxazolamide group is decreased, andthere is a statistically significant difference (P<0.05).

Compared with the normoxia control group, the hypoxia model group, theAcetazolamide positive drug control group, the normoxia PQQ drug groupand the normoxazolamide group have lower serum lactic acid levels, andhas statistically significant (P <0.05). After hypoxia exposure, theserum lactic acid content of PQQ drug dose group I, II, III, IV isincreased (P<0.05). The serum lactic acid content in drug dose group Vcompared with normoxia control group is not statistically significantdifference(P>0.05). Compared with the hypoxia model group, the serumlactic acid content of each PQQ drug dose group after hypoxia exposureis increased, and there is a statistically significant difference(P<0.05), the serum lactic acid content in acetazolamide positive drugcontrol group has no statistically significant difference (P>0.05).

7.12 Effects of PQQ on Liver Energy Metabolism Indexes of Rats Exposedto Acute Altitude Hypoxia

TABLE 38 Effects of PQQ on liver ATP and glycogen in male rats exposedto acute altitude hypoxia ATP Glycogen Group (g/ml) (ng/ml) Normoxiacontrol group (equal 3.81 ± 0.90 2.31 ± 0.57 volume of water) Hypoxiamodel group(equal 3.38 ± 0.56 2.03 ± 0.35 volume of water) PQQ drug dosegroup I(0.91 mg/kg) 3.65 ± 0.62 2.41 ± 0.41 PQQ drug dose group II(1.83mg/kg) 3.71 ± 0.30 2.23 ± 0.17 PQQ drug dose group III(3.66 mg/kg) 4.46± 1.50  2.70 ± 0.84# PQQ drug dose group IV(7.31 mg/kg)   5.04 ±0.79**##   2.86 ± 0.43*## PQQ drug dose group V(14.63 mg/kg)  4.09 ±0.49#  2.55 ± 0.28## Acetazolamide positive drug 3.48 ± 0.44 2.14 ± 0.21control group(0.11 g/kg) *p < 0.05, **p < 0.01 VS normoxia controlgroup, #p < 0.05, ##p < 0.01 VS hypoxia model group

It can be seen from Table 38 that compared with the normoxia controlgroup, the ATP value in the liver of male rats in the PQQ drug dosegroup has a rising trend, and the increase in the content of the PQQdrug dose group IV has a statistically significant difference (P<0.05).Compared with the hypoxia model group, the ATP content in the liver ofmale rats in PQQ drug dose group IV and PQQ drug dose group V isincreased (P<0.05), and there is no statistically significant differencein other groups (P>0.05).

Compared with the normoxia control group, the glycogen value in theliver of male rats in the PQQ drug dose group IV is increased (P<0.05),and there is no statistically significant difference in the other groups(P>0.05). Compared with the hypoxia model group, the glycogen value inthe liver of male rats in PQQ drug dose group III, PQQ drug dose groupIV, and PQQ drug dose group V is increased, has a statisticallysignificant difference (P<0.05). There is no statistically significantdifference in other groups (P>0.05).

TABLE 39 Effects of PQQ on liver ATP and glycogen in female rats exposedto acute altitude hypoxia ATP Glycogen Group (g/ml) (ng/ml) Normoxiacontrol group (equal 1.37 ± 0.27 2.68 ± 0.42 volume of water) Hypoxiamodel group(equal  1.87 ± 0.36**   3.5 ± 0.57** volume of water) PQQdrug dose group I(0.91 mg/kg)  1.48 ± 0.19#  2.52 ± 0.36## PQQ drug dosegroup II(1.83 mg/kg) 1.58 ± 0.27 2.89 ± 0.57 PQQ drug dose groupIII(3.66 mg/kg) 1.64 ± 0.37 2.84 ± 0.67 PQQ drug dose group IV(7.31mg/kg)   1.8 ± 0.20**  3.07 ± 0.19* PQQ drug dose group V(14.63 mg/kg) 1.87 ± 0.26**  3.62 ± 0.38** Acetazolamide positive drug  1.87 ± 0.26** 3.71 ± 0.27** control group(0.11 g/kg) Normoxia PQQ drug group(3.661.62 ± 0.13 2.89 ± 0.28 mg/kg) Normoxia acetazolamide 1.39 ± 0.54 2.75 ±1.13 group(0.11 g/kg) *p < 0.05, **p < 0.01 VS normoxia control group,#p < 0.05, ##p < 0.01 VS hypoxia model group

It can be seen from Table 39 that compared with the normoxia controlgroup, the ATP content in the liver of female rats in the hypoxia modelgroup, post-hypoxic exposure PQQ drug dose group IV, PQQ drug dose groupV and the acetazolamide positive drug control group is increased(P<0.05), and there is no statistically significant difference in othergroups (P>0.05). Compared with the hypoxia model group, the ATP contentin the liver of female rats in the PQQ drug dose group I is decreased(P<0.05), and there is no statistically significant difference in theother groups (P>0.05).

Compared with the normoxia control group, the glycogen value in theliver of female rats in the hypoxia model group, PQQ drug dose group IV,PQQ drug dose group V and the acetazolamide positive drug control groupis increased, and has statistically significant difference (P<0.05),there is no statistically significant difference in other groups(P>0.05). Compared with the hypoxia model group, the glycogen value inthe liver of female rats in PQQ drug dose group I after hypoxia exposureis decreased (P<0.05), and there is no statistically significantdifference in the other groups (P>0.05).

7. 13 Exhaustive Swimming Experiment on Effects of PQQ on the WorkingAbility of Mice Under Altitude Hypoxia Conditions

Exhaustive swimming experiment on the effect of PQQ on the workingability of mice under the condition of high altitude hypoxia

TABLE 40 Changes of body weight of male mice in exhaustive swimmingexperiment male (g) Group 1 day 7 days Negative control (equal volume21.08 ± 1.01 28.11 ± 2.18 of water) Acetazolamide positive drug 21.28 ±1.38  23.05 ± 4.41** control group(0.16 g/kg) PQQ drug dose group I(1.32mg/kg) 22.02 ± 1.51  24.17 ± 3.03** PQQ drug dose group II(2.64 mg/kg)21.19 ± 1.25  25.56 ± 2.02* PQQ drug dose group III(5.28 mg/kg) 20.89 ±1.11  25.92 ± 2.54* PQQ drug dose group IV(10.56 mg/kg) 21.55 ± 0.9325.50 ± 3.80 PQQ drug dose group V(21.12 mg/kg) 20.85 ± 1.15 26.36 ±4.29 *p < 0.05, **p < 0.01 VS negative control group

It can be seen from Table 40 that compared with the negative controlgroup, there is no statistically significant difference in the bodyweight of male mice before gavage administration (P>0.05). Afterintragastric administration for 7 days, compared with the negativecontrol group, the weight of male mice in the acetazolamide positivedrug control group, the PQQ drug dose group I, the PQQ drug dose groupII and the PQQ drug dose group III is decreased, there is statisticallysignificant difference (P<0.05); and there is no statisticallysignificant difference of the PQQ drug dose groups (P>0.05).

8. Summary of Experimental Results

8.1 Experiment of PQQ Anti-Acute Altitude Hypoxia Injury in Rats

8.1.1 Experiment of PQQ Anti-Acute Altitude Hypoxia Injury in Male Rats

PQQ intervention for 7 days did not affect the weight of male rats, andthe administration of acetazolamide could cause the weight of male ratsdecreased.

Acute hypoxia exposure has no significant effects on the blood glucoselevel of male rats, and the intervention of PQQ and acetazolamide has nosignificant effects on the blood glucose level of male rats.

Acute hypoxic exposure has no significant effects on the serum totalprotein content of male rats. Low-dose PQQ intervention can slightlyreduce the serum total protein content of male rats exposed to hypoxia.High-dose PQQ interferes with the serum total protein content in rats isthe same as that of the hypoxia model group. The effect of acetazolamideon the serum total protein content of male rats exposed to hypoxia isnot found. Hypoxia exposure can cause a slight increase in serum albumincontent, and low-dose PQQ intervention can reduce the effect of hypoxiaexposure on the increase in serum albumin content in male rats. Theeffect of acetazolamide on the serum total protein content of male ratsexposed to hypoxia is not found.

Acute hypoxia exposure has no significant effects on triglycerides inmale rats, and the effect of PQQ and acetazolamide intervention ontriglycerides in rats exposed to hypoxia is not found. Acute hypoxiaexposure does not affect the content of total cholesterol andhigh-density lipoprotein cholesterol, but can slightly reduce thecontent of low-density lipoprotein cholesterol. PQQ low-doseintervention has the effects of reducing the amount of total cholesteroland high-density lipoprotein cholesterol, and has no significant effectson the amount of low density lipoprotein cholesterol, the interventionof acetazolamide has no significant effect on the above indicators.

Acute hypoxic exposure has no significant effects on glutamic-pyruvictransaminase, and the affect of PQQ intervention on serumglutamic-pyruvic transaminase, glutamic oxalacetic transaminase andtotal bilirubin in male rats exposed to acute hypoxia is not found.Acetazolamide has the effects of increasing serum glutamic oxalacetictransaminase in hypoxia exposed male rats, and has no significanteffects on glutamic pyruvic transaminase and total bilirubin.

Acute hypoxia exposure has no significant effect on serum urea nitrogenand creatinine in male rats, but can cause a slight increase in uricacid content. PQQ intervention has no significant effect on serum ureanitrogen and creatinine in hypoxia exposed male rats, and low-doseintervention has the effects of reduce serum uric acid content.Acetazolamide can reduce the serum uric acid level of hypoxia exposedrats and increase the serum urea nitrogen content, and has nosignificant effect on serum creatinine;

Acute hypoxia exposure has no significant effects on the activities ofserum lactate dehydrogenase, creatine kinase and α-hydroxybutyratedehydrogenase in male rats. The effects of PQQ and acetazolamideintervention on serum lactate dehydrogenation creatine kinase, andα-hydroxybutyrate dehydrogenase in hypoxia exposed male rats has notbeen found.

Acute hypoxia exposure can slightly increase the serum homocysteinelevel of male rats. The effects of PQQ and Acetazolamide intervention onserum homocysteine of hypoxia exposed male rats have been not found.

Acute hypoxia exposure has no significant effect on serum endothelin-1and nitric oxide levels in male rats. PQQ intervention has nosignificant effects on the above indicators. Acetazolamide has theeffects of slight reduction serum endothelin-1 and nitric oxide contentin hypoxia exposed male rats.

Acute hypoxia exposure has no significant effects on serum superoxidedismutase, total antioxidants, and malondialdehyde in male rats. PQQintervention can increase the activity of serum superoxide dismutase inhypoxia exposed male rats, and have no significant effect to serum totalantioxidants and malondialdehyde. Acetazolamide can also have theeffects of increasing the activity of serum superoxide dismutase in malerats, and has no significant effects on serum total antioxidants andmalondialdehyde.

Acute hypoxic exposure has no significant effects on serum ATP andlactic acid content in male rats. PQQ intervention has no significanteffects on the above indicators in male rat serum. Acetazolamideintervention has no significant effects on serum ATP and has the effectsof reducing serum lactic acid content.

Acute hypoxia exposure has no significant effects on liver ATP andglycogen content of male rats. PQQ intervention can increase liver ATPand glycogen content of male rats. Acetazolamide intervention has nosignificant effects on liver ATP and glycogen content of male rats.

8.1.2 Experiment of PQQ Against Acute Altitude Hypoxia Injury in FemaleRats

PQQ intervention for 7 days did not affect the body weight of femalerats, and Acetazolamide had no significant effects on the body weight offemale rats.

Acute hypoxia exposure can reduce the serum blood glucose level offemale rats. PQQ intervention has the effects of increasing bloodglucose in acute hypoxia exposed female rats. Acetazolamide interventionhas no significant effects on the increase of blood glucose under acutehypoxia exposure. The normoxia PQQ intervention had no significanteffects on the blood glucose of female rats. The intervention of thenormoxia acetazolamide group has the effects of lowering the bloodglucose of female rats.

Acute hypoxic exposure has no significant effects on the serum totalprotein content of female rats. Low-dose PQQ intervention can slightlyreduce the serum total protein content of hypoxia exposed female rats.High-dose PQQ interferes serum total protein content in rats is the sameas the hypoxia model group. The effects of acetazolamide on serum totalprotein content of female rats has been not found. Hypoxic exposure cancause a slight increase in serum albumin, and low-dose PQQ interventioncan reduce the effect of serum albumin in female rats increase caused byhypoxic exposure. Acetazolamide intervention also has this effects. Thenormoxia PQQ intervention has no significant effects on the total serumprotein content of female rats. normoxia acetazolamide can slightlyincrease the serum albumin content of female rats.

Acute hypoxia exposure can reduce the content of total cholesterol andlow-density lipoprotein cholesterol in female rats, without affectingthe content of high-density lipoprotein cholesterol. PQQ interventionhas no significant effects on the above indicators. Acetazolamideintervention has the effects of increasing the content of totalcholesterol, low-density lipoprotein cholesterol and high-densitylipoprotein cholesterol. Noroxic PQQ intervention has no significanteffects on the above indicators. Normoxia acetazolamide has nosignificant effects on the amount of low-density lipoproteincholesterol, and can increase the total cholesterol and high-densitylipoprotein cholesterol content of female rats.

Acute hypoxia exposure has no significant effects on glutamic-pyruvictransaminase in female rats, and can slightly reduce the activity ofglutamic oxalacetic transaminase. The affect of PQQ intervention on theserum glutamic-pyruvic transaminase and glutamic oxalacetic transaminaseactivities of acute hypoxia exposed female rats has been not found.Noroxic PQQ intervention has the effects of slightly increasing theactivity of aspartate aminotransferase, but has no significant effect onglutamic-pyruvic transaminase. Normoxia acetazolamide has no significanteffects on the above indicators.

Acute hypoxia exposure has no significant effects on serum urea nitrogenin female rats, and can cause a slight decreased in content ofcreatinine and uric acid. PQQ intervention has no significant effects onserum urea nitrogen, creatinine and uric acid in hypoxia exposed femalerats. Acetazolamide has the effects of decreasing serum uric acid levelin hypoxia exposed female rats, and increasing the serum urea nitrogenand creatinine value. The normoxia PQQ intervention has no significanteffects on the above indicators. Normoxia acetazolamide has the effectsof reducing the serum uric acid level of female rats and increasing theserum urea nitrogen and creatinine values.

Acute hypoxia exposure can reduce the activity of serum creatine kinaseand α-hydroxybutyrate dehydrogenase in female rats, and has nosignificant effects on the activity of serum lactate dehydrogenase. Thesignificant effects of PQQ intervention on the activity of serum lacticdehydrogenase, creatine kinase, and α-hydroxybutyrate dehydrogenase hasbeen not found. Acetazolamide has no significant effects on the aboveindicators. The normoxia PQQ intervention has the effects of increasingthe above indicators. Normoxia acetazolamide has no significant effectson the above indicators.

Acute hypoxia exposure can slightly reduce the level of homocysteine infemale rats. PQQ and acetazolamide intervention have no significanteffects on serum homocysteine in hypoxia exposed female rats. Theintervention of normoxia PQQ and acetazolamide had no significanteffects on the above indicators.

Acute hypoxic exposure can reduce the serum endothelin-1 content offemale rats, but has not been found to have a significant impact on thenitric oxide content. PQQ intervention can increase the serumendothelin-1 content of rats after acute hypoxia exposure, and has nosignificant effect to nitric oxide. Acetazolamide intervention has nosignificant effects on the above indicators. The intervention ofnormoxia PQQ and acetazolamide can reduce the serum endothelin-1 contentof female rats, and no significant effects on the content of nitricoxide has been found.

Acute hypoxia exposure has no significant effects on serum superoxidedismutase, total antioxidants, and malondialdehyde in female rats. PQQintervention can increase serum superoxide dismutase activity in hypoxiaexposed female rats, and have no significant effects on serum totalantioxidants and malondialdehyde. Acetazolamide can also have theeffects of increasing the activity of serum superoxide dismutase, andhas no significant effects on serum total antioxidants andmalondialdehyde. Noroxic PQQ intervention can slightly increase theeffects of malondialdehyde in female rats, and has no significanteffects on serum superoxide dismutase and total antioxidants.Noroxazepine has no significant effects on the above indicators.

Acute hypoxia exposure has no significant effects on serum ATP in femalerats, and has the effects of reducing serum lactic acid content. PQQintervention has the effects of increasing serum ATP and lactic acidcontent in female rats. Acetazolamide has no significant effects on theabove indicators. The normoxia PQQ intervention has the effects ofreducing the serum lactic acid content, but has no significant effect onthe serum ATP content. The Acetazolamide intervention has the effects ofreducing the serum ATP and lactic acid content of female rats.

Acute hypoxia exposure can increase the liver ATP and glycogen contentof female rats. After hypoxia exposure and the intervention of normoxiaPQQ and Acetazolamide have no significant effects on the liver ATP andglycogen content of female rats.

8.2 Exhaustive Swimming Experiment of PQQ to Improve the Working Abilityof Mice under Altitude Hypoxia Conditions

Exhausted swimming test of male mice exposed to 6000 meters above sealevel (administered 1.32 mg/kg, 2.64 mg/kg, 5.28 mg/kg, 10.56 mg/kg,21.12 mg/kg PQQ, administration for 7 days). The results shows that themice in the negative control group and the acetazolamide positive drugcontrol group died earlier, the start time of exhaustion swimming deathof mice in each dose group of PQQ is delayed compared with the above twogroups. After exposure to 6000 meters above sea level for180 minutes,the mice in the negative control group and the acetazolamide positivedrug control group are almost completely dead, and the mice in the eachPQQ dose groups are completely dead about 400 minutes. Exhaustedswimming survival time (minutes)of male mice in the negative controlgroup, acetazolamide positive drug control group, and mice in the PQQabove five dose groups are 133.38±110.94, 130.64±79.46, 199.21±98.54,273.10±63.07, 173.15±116.32, 195.04±59.81, 263.20±48.27. The increasingrate of survival time was 0%, 2.10%, 52.49%, 109.05%, 32.54%, 49.30%,101.47%. The results of this experiment suggest that the administrationof PQQ can prolong the survival time of mice after exhausting swimming,and has the effects of improving the working ability of mice under highaltitude hypoxia exposure conditions.

The present invention is illustrated by the above examples, but itshould be understood that the present invention is not limited to thespecific examples and implementations described herein. The purpose ofincluding these specific examples and embodiments here is to help thoseskilled in the art practice the present invention. Any person skilled inthe art can easily make further improvements and improvements withoutdeparting from the spirit and scope of the present invention. Therefore,the present invention is only limited by the content and scope of theclaims of the present invention, and it is intended to cover all thoseincluded in the appendix Alternatives and equivalents within the spiritand scope of the present invention as defined by the claims.

We claim:
 1. The application of pyrroloquinoline quinone in thepreparation of medicines for preventing and treating acute altitudesickness.
 2. The application of pyrroloquinoline quinone in thepreparation of drugs for the prevention and treatment of acute altitudehypoxia injury.